Living in Porpoise Spit, Australia, twenty-two year old Muriel Heslop is a socially awkward (she unfashionably and unabashedly listens to ABBA music), slightly overweight, directionless woman with few life or professional skills. Her lack of self-esteem is fostered by the constant verbal abuse directed at her - and at her siblings - by their politician father, who blames whatever political problems he has on his family, who he deems to be a public embarrassment to him. Muriel's self-esteem takes a further blow when her so-called friends - the popular girls from high school - exclude her from their social circle. Muriel resorts to theft to make herself happy. Her life changes when she runs into another colleague from high school, Rhonda Epinstock. Also not in the popular social circle in high school, Rhonda is now a gregarious, carefree girl who can see Muriel's desire for an equally carefree life. The two move to Sydney together. Out from under the direct criticism of her father, Muriel feels that she can now put behind her all the problems of "Muriel Heslop", even changing her name to Mariel to escape those problems. She also feels she can now achieve true happiness, her primary goal being to get married. Despite continuing problems with her family and a new serious issue with Rhonda, Muriel seizes on what she sees as an opportunity to achieve her primary goal. But a further issue with her family makes Muriel finally come to the realization of what is truly important in her life.